The increased interest in environmental awareness, and a reluctance to rely on non-renewable sources of energy, has led to greater usage of renewable energy systems, e.g. solar power, wind power, thermal power, and tidal power. The latter involves the installation of turbine generators in an area of tidal flow, and converts the energy of the tides into electrical power.
With reference to FIG. 1, a direct-drive shaftless permanent magnet hydroelectric turbine generator is described in PCT Application No. PCT/EP2007/006258. The generator 10 comprises a ring-shaped stator 12 and a rotor 14, the stator 12 having a plurality of coils (not shown) located about the circumference of the stator 12. The rotor 14 comprises an inner rim 16, which defines an open centre. The rotor 14 further comprises an array of generally radially extending blades 18 captured between the inner rim 16 and an outer rim 20. The rotor 14 further comprises an array of magnets (not shown) disposed about the outer rim 20. The stator 12 concentrically surrounds the rotor 14, with the plurality of coils providing a magnetic flux return path for the magnets.
The generator 10 is positioned in an area of tidal flow, such that the motion of the seawater through the generator 10 acts on the blades 18, resulting in rotation of the rotor 14 within the stator 12. The motion of the magnets relative to the coils of the stator 12 causes the magnetic field generated by the magnets to induce an EMF in each of the coils. These induced EMFs provide the electrical power output from the turbine generator 10.
In the interests of accepted good practice, it is understood that certain safety rules should be followed when undertaking the installation and connection of high voltage electrical equipment, e.g. the equipment should be switched out from all possible points of supply; isolated from all possible points of supply; safeguarded by safety padlocks being applied at switch points; and connected to earth by circuit main earths.
While the above criteria can be easily adhered to when dealing with above sea electrical equipment, the problem associated with isolation of an underwater turbine generator largely comes from the inaccessibility of switchgear, and the need to energise and de-energise the turbine generator from a significant distance away (e.g. from an on-shore power substation).
It is therefore the object of this method patent to provide a method for installing and connecting a hydroelectric turbine generator that provides certainty and safety, and reduces the operations required in potentially hazardous conditions.